• Journal of Korea Port Economic Association
• /
• v.34 no.4
• /
• pp.141-160
• /
• 2018

In this paper, to analyze the perception and response strategy of Korean ship owners on Global Sulphur Cap 2020, examined the IMO environmental regulation status focusing on MARPOL Annex VI regulation about air pollution prevention, technological measures to reduce SOx emission, shipping industry and management status of Korean ship owners. First of all, the questionnaire was conducted for Korean ship owners after selecting the evaluation factors. The purpose of this study was to investigate the difference of the perception and response strategy of Korean ship owners by corporation size and main vessel type using frequency and cross analysis. It is confirmed that various researches on SOx emission reduction have been carried out from various points of view at home and abroad. In this study, existing studies related to technical factors for regulatory response and economics analysis were examined and evaluation factors were selected. As a result of analysis, it is found that large-sized shipping companies are more prepared for regulatory response than small and medium-sized bulk carrier owners. There were similar perception and the direction of response strategy about the impacts by corporation size and main vessel type. In about two years to be implemented in 2020, It is necessary to find an appropriate response strategy based on the support policy of the government and related organizations and the systematic analysis of the ship owners. Through this study, although the difference between the perception and response strategy of the ship owners by corporation size and main vessel type was understood, it was found that there were limitations on specific response strategy and corporate data collection. In future research, we should overcome the limitations of this study and conduct an in-depth study.

• Horticultural Science & Technology
• /
• v.19 no.4
• /
• pp.596-601
• /
• 2001

This study was carried out to determine the effect of base carriers such as zeolite or vermiculite on change of concentration of polyoxyethylene laury ether[$C_{12}H_{25}O(C_{2}H_{4}O)_{3}H$, PLE] and on initial wetting of peat-vermiculite medium in the development of a soil wetting agent using the mixture of PLE and polyoxyethylene+polyppro-pyleneoxide tridecylether (1:1, w/w, CM-1). The concentration of PLE in the treatment of vermiculite was higher than that of zeolite during the period from 2 to 6 weeks. The cumulative concentration of PLE released in the treatment of vermiculite was about $2800mg{\cdot}L^{-1}$ and zeolite was about $2300mg{\cdot}L^{-1}$. The treatments of PLE+CM-1 with zeolite or vermiculite as a carrier were effective in initial water retention of root media having more than 510 mL of water per pot, where as those of $AquaGro^{G}$ and control had 490 mL and 400 mL of water per pot, respectively. In the evaporative water loss, the treatment of zeolite and $AquaGro^{G}$ were faster than that of control and vermiculite. The control treatment had the fastest water movement in and the highest volume of water infiltrating into root medium among all treatments. Increased application rate of PLE+CM-1 did not increase water retention capacity. The treatment of $0.6g{\cdot}L^{-1}$ had the highest evaporative water loss and that of $0.3g{\cdot}L^{-1}$ had the highest amount of water infiltrating into root media among all other treatments.

• Journal of Genetic Medicine
• /
• v.4 no.2
• /
• pp.133-141
• /
• 2007

Purpose : Cri-du-Chat syndrome (CdCs) is a rare but clinically recongnizable condition with an estimated incidence of 1:50,000 live births. The clinical characteristics of the syndrome include severe psychomotor and mental retardation, microcephaly, hypertelorism, hypotonia, and slow growth. Also the size of the chromosome 5p deletion ranges were known from the region 5p13 to the terminal region. In this study, we report the spectrum of 5p deletion in Korean 20 pts. with CdCs and genotype-phenotype associations in CdCs. Methods : In order to delineate genotype-phenotype correlation, molecular cytogenetic studies including GTG banding and clinical characterization were performed on Korean 20 pts with CdCs including parents. CGH array and Fluorescence in situ hybridization (FISH) analysis were used to confirm a terminal deletion karyotype and map more precisely the location of the deletion breakpoint. Results : Molecular analysis of the spectrum of 5p deletion revealed 9 pts (45%) with a del (5)(p14), 7 pts. (35%) a del (5)(p13), 3 pts. (15%) a del (5)(p15.1) and 1 pt. (5%) a del (5)(p15.2) in 20 pts with CdCs. 4(20%)pts were identified to have additional chromosome abnormalites of deficiency and duplication involving chromosomes of 6, 8, 18, & 22. Parental study identified 3 familial case (2 paternal and 1 maternal origin) showing parents being a balanced translocation carrier. And the comparison study of the deletion break points among these 20 pts. with their phenotype has showed the varying clinical pheno-types in the CdCs critical region. Conclusion : The characterization of 5p deletion including parental study may help to delineate the genotypephenotype correlation in CdCs. Also these molecular cytogenetic analyses will be able to offer better information for accurate genetic diagnosis in CdCs and further make possible useful genetic counseling in pts. and family.

• The Korean Journal of Nuclear Medicine
• /
• v.38 no.3
• /
• pp.253-258
• /
• 2004

Purpose: Chitosan has been studied as a non-viral gene delivery vector, drug delivery carrier, metal chelator, food additive, and radiopharmaceutical, among other things. Recently, galactose-graft chitosan was studied as a non-viral gene and drug delivery vector to target hepatocytes. The aim of this study was to investigate the usefulness of nuclear imaging for in vivo evaluation of targeting the hepatocyte by galactose grafting. Methods and Materials: Galactosyl methylated chitosan (GMC) was produced by methylation to lactobionic acid coupled chitosan. Cytotoxicity of $^{99m}Tc$-GMC was determined by MTT assay. Rabbits were injected via their auricular vein with $^{99m}Tc$-GMC and $^{99m}Tc$-methylated chitosan (MC), the latter of which does not contain a galactose group, and images were acquired with a gamma camera equipped with a parallel hole collimator. The composition of the galactose group in galactosylated chitosan (GC), as well as the tri-, di-, or mono-methylation of GMC, was confirmed by NMR spectroscopy. Results: The results of MTT assay indicated that $^{99m}Tc$-GMC was non-toxic. $^{99m}Tc$-GMC specifically accumulated in the liver within 10 minutes of injection and maintained high hepatic uptake. In contrast, $^{99m}Tc$-MC showed faint liver uptake. $^{99m}Tc$-GMC scintigraphy of rabbits showed that the galactose ligand principally targeted the liver while the chitosan functionalities led to excretion through the urinary system. Conclusion: Bioconjugation with a specific ligand endows some degree of targetability to an administered molecule or drug, as in the case of galactose for hepatocyte in vivo, and evaluating said targetabililty is a clear example of the great benefit proffered by nuclear imaging.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.22 no.2
• /
• pp.78-83
• /
• 2012

The structural change and the electrical conductivity with Sr content in $La_{1-x}Sr_xMn_{0.8}Cu_{0.2}O_3$ (LSMCu) were studied. $La_{0.8}Sr_{0.2}MnO_3$ (LSM) and $La_{1-x}Sr_xMn_{0.8}Cu_{0.2}O_3$ ($0.1{\leq}x{\leq}0.4$) were synthesized by EDTA citric complexing process (ECCP). A decrease in the lattice parameters and lattice volumes was observed with increase of Sr content, and these results were attributed to the increasing $Mn^{4+}$ ions and $Cu^{3+}$ ions in B-site. The electrical conductivity measured from $500^{\circ}C$ to $1000^{\circ}C$ was increased with increase of Sr content in the $0.1{\leq}x{\leq}0.3$ composition range, and it was 172.6 S/cm (at $750^{\circ}C$) and 177.7 S/cm (at $950^{\circ}C$, the maximum value) in x = 0.3. The electrical conductivity was decreased in x = 0.4 because of the presence of the second phase in the grain boundaries. The lattice volume was contracted by increase of $Mn^{4+}$ ions and $Cu^{3+}$ ions in B-site according to increase of Sr content and the electrical conductivity was increased with increase of charge carriers which were involved in the hopping mechanism.

• Journal of Veterinary Clinics
• /
• v.28 no.5
• /
• pp.486-496
• /
• 2011

A special mesenchymal tissue layer called perichondrium has a chondrogenic capacity and is a candidate tissue for engineering of cartilage. To overcome limited potential for chondrocyte proliferation and re-absorption, we studied a method of cartilage tissue engineering comprising chondrocyte-hydrogel pluronic complex (CPC) and cultured perichondrial cell sheet (cPCs) which entirely cover CPC. For effective cartilage regeneration, cell-sheet engineering technique of high-density culture was used for fabrication of cPCs. Hydrogel pluronic as a biomimetic cell carrier used for stable and maintains the chondrocytes. The human cPCs was cultured as a single layer and entirely covered CPC. The tissue engineered constructs were implanted into the dorsal subcutaneous tissue pocket on nude mice (n = 6). CPC without cPCs were used as a controls (N = 6). Engineered cartilage specimens were harvested at 12 weeks after implantation and evaluated with gross morphology and histological examination. Biological analysis was also performed for glycosaminoglycan (GAG) and type II collagen. Indeed, we performed additional in vivo studies of cartilage regeneration using canine large fullthickness chondrial defect model. The dogs were allocated to the experimental groups as treated chondrocyte sheets with perichondrial cell sheet group (n = 4), and chondrocyte sheets only group (n = 4). The histological and biochemical studies performed 12 weeks later as same manners as nude mouse but additional immunofluorescence study. Grossly, the size of cartilage specimen of cPCs covered group was larger than that of the control. On histological examination, the specimen of cPCs covered group showed typical characteristics of cartilage tissue. The contents of GAG and type II collagen were higher in cPCs covered group than that of the control. These studies demonstrated the potential of such CPC/cPCs constructs to support chondrogenesis in vivo. In conclusion, the method of cartilage tissue engineering using cPCs supposed to be an effective method with higher cartilage tissue gain. We suggest a new method of cartilage tissue engineering using cultured perichondrial cell sheet as a promising strategy for cartilage tissue reconstruction.

• Tuberculosis and Respiratory Diseases
• /
• v.47 no.5
• /
• pp.618-628
• /
• 1999

Background: Cell growth is a balance between cell proliferation and cell death. Insulin-like growth factor-I(IGF-I), which binds IGF-I receptor(IGF-IR), mediates cellular proliferation as a potent mitogen. IGF binding protein-3(IGFBP-3) as a circulating major IGFBP can inhibit or enhance the effects of IGF-I on cellular growth by binding IGFs. Methods: We investigated the expressions of mRNA of IGF-I and IGF-IR by northern blot and phosphorylation of IGF-IR with the treatment of IGF-I by western blot in 3T3 fibroblast cells. The cellular proliferations of 3T3 cells with the treatments of IGF-I were evaluated using $^3H$-thymidine incorporation and MTT assay. Also to observe the effect of IGFBP-3 on cellular proliferation, 3T3 cells were treated with anti-IGFBP-3 and ${\alpha}IR_3$(monoclonal antibody to IGF-IR) alone or in combination. Results: Our results demonstrated that 3T3 cells showed mRNA expressions of IGF-I and IGF-IR and the IGF-I increased phosphorylation of IGF-IR. The treatments of 3T3 cells with IGF-I increased cellular proliferation in 5 % and 1 % seruma-containing media, not in serum-free media. The addition of anti-IGFBP-3 to neutralize IGFBP-3 showed 2-fold increase of cellular proliferation, and also co-incubation of anti-IGFBP-3 and ${\alpha}IR_3$ together showed similar increase of cellular proliferation in 3T3 cells. Interestingly, when the cells were pretreated with ${\alpha}IR_3$ for 4 hr, prior to the simultaneous addition of ${\alpha}IR_3$ and anti-IGFBP-3, anti-IGFBP-3-mediated cellular proliferation was decreased to control level. All of these results suggest that free IGF-I released from IGF-I/IGFBP-3 complex would be involved in the cellular proliferation. Conclusion: IGF-I is a mitogen through the activation of IGF-IR in 3T3 cells, and IGFBP-3 could be a potent inhibitor for IGF-I action by binding IGF-I.

• Korean Journal of Materials Research
• /
• v.11 no.5
• /
• pp.419-426
• /
• 2001

The stochiometric $AgGaSe_2$ polycrystalline mixture of evaporating materials for the $AgGaSe_2$ single crystal thin film was prepared from horizontal furnace. To obtain the single crystal thin films, $AgGaSe_2$ mixed crystal and semi-insulating GaAs(100) wafer were used as source material and substrate for the Hot Wall Epitaxy (HWE) system, respectively. The source and substrate temperature were fixed at$ 630^{\circ}C$ and $420^{\circ}C$, respectively. The thickness of grown single crystal thin films is 2.1$\mu\textrm{m}$. The single crystal thin films were investigated by photoluminescence and double crystal X-ray diffraction(DCXD) measurement. The carrier density and mobility of AgGaSe$_2$ single crystal thin films measured from Hall effect by van der Pauw method are $4.89\Times10^{17}$ cm$^{-3}$ , 129cm2/V.s at 293K, respectively. From the Photocurrent spectrum by illumination of perpendicular light on the c-axis of the AgGaSe$_2$ single crystal thin film, we have found that the values of spin orbit splitting $$\Delta$S_{o}$ and the crystal field splitting $\Delta$C$_{r}$, were 0.1762eV and 0.2474eV at 10K, respectively. From the photoluminescence measurement of AgGaSe$_2$ single crystal thin film, we observed free excision (EX) observable only in high quality crystal and neutral bound exciton ($D^{o}$ , X) having very strong peak intensity. And, the full width at half maximum and binding energy of neutral donor bound excition were 8mev and 14.1meV, respectively. By Haynes rule, an activation energy of impurity was 141 meV.ion energy of impurity was 141 meV.

• Journal of the Korean Vacuum Society
• /
• v.17 no.4
• /
• pp.359-364
• /
• 2008

We have investigated optical and structural properties of $Al_{0.3}Ga_{0.7}N$/GaN and $Al_{0.3}Ga_{0.7}N/GaN/Al_{0.15}Ga_{0.85}N/GaN$ heterostructures (HSs) grown by metal-organic chemical vapor deposition, by means of Hall measurement, high-resolution X-ray diffraction, and temperature- and excitation power-dependent photoluminescence (PL) spectroscopy. A strong GaN band edge emission and its longitudinal optical phonon replicas were observed for all the samples. At 10 K, a 2DEG-related PL peak located at ${\sim}\;3.445\;eV$ was observed for $Al_{0.3}Ga_{0.7}N$/GaN HS, while two 2DEG peaks at ${\sim}\;3.42$ and ${\sim}\;3.445\;eV$ were observed for $Al_{0.3}Ga_{0.7}N/GaN/Al_{0.15}Ga_{0.85}N/GaN$ HS due to the additional $Al_{0.15}Ga_{0.85}N$ layers. Moreover, the emission intensity of the 2DEG peak was higher in $Al_{0.3}Ga_{0.7}N/GaN/Al_{0.15}Ga_{0.85}N/GaN$ HS than in $Al_{0.3}Ga_{0.7}N$/GaN HS probably due to an effective confinement of the photo-excited holes by the additional $Al_{0.15}Ga_{0.85}N$ layers. The 2DEG-related emission intensity decreased with increasing temperature and disappeared at temperatures above 150 K. To investigate the origin of the new 2DEG peaks, the energy-band structure for multiple AlGaN/GaN HSs were simulated and compared with the experimental data. As a result, the observed high- and low-energy peaks of 2DEG can be attributed to the spatially-separated 2DEG emissions formed at different AlGaN/GaN heterointerfaces.

• Childhood Kidney Diseases
• /
• v.3 no.2
• /
• pp.209-216
• /
• 1999

Purpose : Nephrogenic diabetes insipidus (NDI) is a rare X-linked disorder associated with renal tubule resistance to arginine vasopressin (AVP). The hypothesis that the defect underlying NDI might be a dysfunctional renal AVPR2 has recently been proven by the identification of mutations in the AVPR2 gene in NDT patients. To investigate the association of mutations in th AVPR2 gene with NDI, we analyzed the AVPR2 gene located on the X chromosome. Methods : We have analyzed the AVPR2 gene in a kindred with X-linked NDI. The proband and proband's mother were analyzed by polymerase chain reaction-single strand conformational polymorphism(PCR-SSCP) and DNA sequencing of the AVPR2 gene. We also have used restriction enzyme analysis of genomic PCR product to evaluate the AVPR2 gene. Results : C to T transition at codon 202, predictive of an exchange of tryptophan 202 by cysteine(R202C) in the third extracellular domain was identified. This mutation causes a loss of Hae III site within the gene. Conclusion : We found a R202C missense mutation in the AVPR2 gene causing X-linked NDI, and now direct mutational analysis is available for carrier screening and early diagnosis.